Crops such as potatoes or beets are cleaned from adhering soil after they were harvested on the field. For this purpose, suitable cleaning apparatuses are used. Machines are known, which are equipped with a charging and supply hopper serving as a collecting container and having an opening at its bottom. From the opening the crops arrive on a transport device for cleaning. The crops are transported by the transport device into a cleaning region. In particular brushes clean the crops in the cleaning region from soil adhering to them.
German utility model DE 20 2005 004 507 U1 discloses a brush-washing and polishing machine for crops. The device described therein for cleaning crops consists of a plurality of brush rollers forming a transportation path. The brush rollers are drivable in rotation and are arranged one after another in a direction of passage of the crops. In a starting position the brush rollers are arranged in one common horizontal plane. This brush-washing and polishing machine for crops is very elaborate in manufacture and also in subsequent maintenance. If one brush roller becomes inoperative, either a crop jam or an imbalanced onward transport occurs, which can lead to a blockage of the machine because the crops are no longer transported.
German patent publication DE 197 14 181 A1 describes a device for cleaning of fruits, particularly crops such as beets. This device for cleaning of fruits comprises a substantially cylindrical or polygonal housing with two housing end walls. Preferably the beet feeding device and the beet discharging device are combined, wherein a fruit support device is arranged in the interior of the housing and is substantially extending over the entire axial length of the housing. The fruit support device is constructed of at least two brush rollers arranged parallel and closely adjacent. At least two brush rollers are designed so that they serve for support, transport and cleaning of the fruit. In this device fruits to be cleaned come to lie on the brushes and are cleaned by them. Therefore, the transport plane of the fruit is above the plane in which the transport and cleaning brushes are arranged. The cleaning pressure loaded on the fruits is determined only by the weight of the fruit. The fruits are rotated by the rotation of the brushes and consequently cleaned on all sides.
German Patent Application 1,607,629 published for opposition teaches a device for washing and cleaning sugar beets. The system includes a drum in which the sugar beets supplied via a conveyor belt are first soaked, and a cleaning grid with spray nozzles arranged above it. The waste water arising below the first portion of the grid is discharged, while the already much cleaner water arising under the second region of the grid is fed to the drum again by a pump. The drum is rotatable about its horizontally arranged longitudinal axis by means of a non-illustrated drive, and is provided at its inner periphery with inserts in the form of a single- or multi-start screw. The screw flights comprise holes through which a uniform water level can be reached in each single cell formed at the bottom of the drum between two turns. The low stirring bars disposed on the inner periphery turn-over the cell contents. The discharge end of the drum is provided with a number of vanes which form an inner scoop wheel. In the region of this discharge end of the drum, the drum periphery comprises holes through which the water can run off. A transport channel protrudes into the discharge end of the drum formed as inner scoop wheel. The transport channel supplies the beets to the grid.
Among the disadvantages of known cleaning apparatuses are that their transportation systems for the crops constructed in very complicated and failure-prone manner. In particular, the brush rollers form the transport system and the cleaning system at the same time. This leads to increased wear of the brush rollers, because such brush rollers are constantly exposed to the pressure of the crops positioned above.